Fountain pen



April 7,1931- R. s. CARTER 1,799,213

FOUNTAIN PEN Filed Dec. 19, 1929 INVENToR,

ATTORNEYS.

Patented Apr. 7, 1931 RUSSELL s. CARTER, E HEWLETT, NEW YORK FOUNTAIN TEN Y' Application mea December 19, 1929. serial; No.y 415,184..

Heretofore it has been proposed to collapse the ink sacks of fountain pens (as a preliminary to refilling) by air pressure developed in the barrels of the pens in various ways. For

example, it has been proposed to build the barrel in two or more telescoping parts, so that by pumping one barrel part on another as it were, a slight super-atmospheric pressure can be produced inside the barrel to l0 collapse the sack. Again, I myself have heretofore proposed to give the pen cap a long sliding lit on the outside of the pen barrel so that (the barrel being perforated to admit air from the cap) the ink sack may be collapsed by sliding the cap overthe barrel.

The sacks being collapsed, these pens are refilled ordinarily by releasing the air pressure, and thus permitting the sacks "to re-expand by their own resiliency while the pen points are submerged in ink. VUniversally the ink sacks have heretofore been cylindrical in shape in their normal or expanded condition. The sack-collapsing force developed Vin the compressed-air type of pen is so small however, that it has been found difficult to so co-relate the sack wall to the pressure as to cause the ink to always ill all of the space available'for it. I have found that this difficultv can be minimized by corrugating the 39 wall or walls of the ink sacks, or in any other.,

way making the ratio of the area ofthe wall surface to the sack volume greater than the corresponding ratio in straight-sided or simple cylinders. i i

3F The accompanying drawings illustrate my present invention as applied to the compressed-air pen heretofore proposed by me; it will be understood however that my present invention is not limited vto this particular 40 pen construction, but is applicable to all forms of compressed-air,pens, i. e. pens in which the sacks are collapsed for refilling by air pressure. Y

In the drawings: Fig. 1 is for the most part a sectional View of the pen, showing its ink v sack in elevation. Fig. 2 is a cross-section of the ink sack of Fig. 1, about on the line II-II. Fig. 3, partly in section, shows the pen of Fig. 1 with the ink sack collapsed preparatory to refilling. Fig. 4 is an elevation'of thepen closed, the vcap beingin sec- Y tion. Fig. 5,partly in elevation and partly in section, illustrates another form of ink sack of Vmyrpresent invention.

As usual, the barrel 1 of the pen is pro-` 55 vided with a linger portion 2 carrying the pen point 3, while the cap 6 is arranged to be fastened over the`penpoint (Fig. 4) by screw threads 7. The end 11 of the barrel is perforated at 13, while the side walls IofV 60. the cap is perforated at 14. The open end ofthe ink sack' fits tightly over the flange 4 of the finger portion 2, in the customary manner. In accordance with the present invention, the outer surface of thisink sack. 5 is corrugatedlongitudinally (Figs. 1 and 2) and the inner,` surface of the wall of the sack correspondsto its outer surface; that is to say in the present instance, the inner surface of the side wall Vor walls of the sack is corrugated in the same manner as the outer surface and the internal and external` cor- `rugations substantially fit into each other (Fig. 2). The thickness of the wall of the sack may beiabout the same throughout the whole sack. The sack 5 being self expanding, thatis to say, when exposed to substantially equal pressures internally and externally, it'tends to restore itself to the shape in which it is illustrated in Figs. 1 and 2, the 80 operation of refilling the pen may be as follows: The cap 6 being placed on the barrel in the position shown in Fig. 1, the perforation 14 is closed by the-finger and then thecap slid over thebarrel to say the position of y .Fig. 3; the shoulder 15 stops the cap 6 before the perforation 14 is closed by the barrel lapping it. Externally the barrel 1 is cylindri cal from the shoulder 15 to the end 11 and internally the cap 6 is cylindrical from its 90 Y open end to the perforation 14; also the internal diameter of the cap 6 is'but slightly greater than the external diameter of the barrel 1. Hence sliding cap 6 from theposition of Fig.V 1 to its position of Fig. 3, with the"v perforation 14 held closed, forces air into the barrel 1 through the perforation 13 and the super-atmospheric pressure thus developed within thebarrel lserves to collapse the ink sack as indicated in Fig. 3. By increasing the ratio of the area of the wall surface of the sack to the sack volume, by the corrugations described, a greater area is effectively presented to this air pressure than were the sack a simple straight-sided cylinder as heretofore, and hence the available air pressure is made more effective for collapsing the sack. The pen point 8 now being submerged in ink, the air pressure within the barrel is released by opening port 14. This permits the ink sack 5 to restore itself to its expanded condition of Fig. l, and in doing so suck up into itself a new charge of ink.

Instead of being corrugated longitudinally the ink sack may be corrugated transversely both internally and externally, as illustrated in Fig. 5. It will be understood however thatmy invention is not limited to the particular forms of it herein illustrated and described, except as appears hereinafter in the claims.

I claim:

1. A fountain pen of the compressed-air type having an ink sack, characterized by the fact that the ratio of the area of the wall surface of the sack to the sack volume is greater than the ratio of wall surface to volume in a straight-sided cylindrical ink sack.

2. A fountain pen of the compressed-air typehaving an ink sack, characterized by the .fact that the ratio of the area of the outer surface of the wall of the sack to the volume ofthe hollow of the sack is greater than the corresponding; ratio of a straightsided cylindrical ink sack, and the inner surfaceof the wall of the sack corresponds to its outer surface.

externally at its side walls and correspond? ingly corrugated internally.

5. The combination with a fountain peu vprovided with means through which a sackcollapsing air pressure can be developed wit-hin the pen barrel, of an ink sack corrugated longitudinally externally and the inner surface of its corrugated walls substantially corresponding` to the outer surface thereof.

6. The combination with a fountain pen provided with means through which a sackcollapsing air pressure can be developed withinthe pen barrel, of a self-expanding ink sack corrugated externally at `its side walls and correspondingly corrugated internally.

7. .In a fountain pen, the combination of an in-k sack, corrugated both internally and externally, a member surroundingthel same, said member being open remote from the pen specilication.

RUSSELL S. CARTER. 

